Filament for incandescent lamps.



UNITED STATES PATENT .OFFIOE.

WILLIS R. WHITNEY, OF SGHENECTADY, NEW YORK, ASSIGNOR T0 GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

FILAMENT FOR INGANI JESCENT LAMPS.

To all whom it may concern: Be it known that I, WILLIS R. WHITNEY, acitizen of the United States, residing at Schenectady, county ofSchenectady, State 'of New York have invented certain new and usefulImprovements in Filaments for 'Incandescent Lamps, of which thefollowing is a s ecification. Y

he metal cerium, when at a red-heat, has the remarkable pure nitrogen anereby forming a nitrid which hasa metallic luster and is a goodelectrical conductor. In this reaction, the compound being exothermic,an enormous heat 1s generated which makes the mass undergoing reactionglow with a brilliancy equal to the are light. As the elements remaincombined in this heat, the nitrid of cerium is stable at excessivelyhigh temperatures andis with difficulty fusible. From this nitrid ofcerium I form the incandesci'ng element or illuminant of incandescent orsimilar lamps by compressing the very finely powdered material mixedwith paraflin, into-rods Specification of Letters Patent. Applicationfiled November 14, 1904. Serial No. 232,618. 1

rolperty of reacting with a suitable binder, as' or filaments. These arePatented Aug. 1a, 1908.

then heated to their sintering oin t by passher e ectric current ing'through them a hi than they are to carry W en'in use. a

Although the nitrrd of cerium constitutes the preferable embodimentof myinvention- I may, in place thereof, use the 'nitrids of other rareearth'metals such as yttrium or lanthanum.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. A filament for incandescent lamps formed substantially of'a nitrid ofa rare earth metal.

f 2. A filament for incandescent lamps formed of nitrid of cerium.

3. An illuminant formed substantiallf% of a nitrid of an element havinga high a nity for nitrogen at high tern eratures.

In witness whereof, have hereunto set my hand'this 12th day of November,1904.

WILLIS R. WHITNEY.

